FREE Exponential Growth & Decay Lesson | Algebra 1 Day 1 | ELL Scaffolded

★ **FREE COMPLETE LESSON — Exponential Growth & Decay, Day 1** ★

Love this free lesson? Grab the full 5-day PBL unit with 4 real-world datasets → [link to paid product]

📋 **WHAT YOU GET (8 PAGES, READY TO PRINT & TEACH)**

This is **Day 1 of a 5-day Project-Based Learning unit on exponential growth and decay**. It's a complete, standalone **55-minute lesson**.

Included in this free download:

✅ Cover page with UM Printables branding ✅ Teacher instructions + standards alignment (**CCSS HSF-LE.A.1, A.3, B.5, BF.A.1a**) ✅ Vocabulary card for **“Exponential Growth”** with formula + common-error tip ✅ Visual concept anchor covering growth vs. decay curves and linear vs. exponential comparison ✅ Complete Day 1 lesson:

* Launch: The legend of the chessboard with data table * Mini-lesson: Deriving **A(t) = A₀ · bᵗ** * Worked example: Bacterial growth modeling * Guided practice: 3 problems for partner work * Exit ticket: 3 self-assessment questions ✅ Detailed answer key with step-by-step solutions (**Given → Formula → Substitution → Interpretation**) ✅ ELL scaffolds: sentence frames, structured discourse stems, and vocabulary pre-teach ✅ Marketing page linking to the full 5-day unit

🎯 **WHY THIS LESSON WORKS**

**The chessboard hook:** The launch uses the legend of the chessboard and grains of wheat to introduce exponential growth through a data table and the concept of doubling.

**Real differentiation:** The vocabulary card includes a **“Common Error to Avoid”** tip, while sentence frames and structured discourse stems support multilingual learners.

**Thinking-focused answer key:** Every solution follows the same **Given → Formula → Substitution → Interpretation** structure.

📏 **STANDARDS ADDRESSED**

**HSF-LE.A.1** — Distinguish linear vs. exponential situations **HSF-LE.A.3** — Observe exponential eventually exceeds linear **HSF-LE.B.5** — Interpret parameters in context **HSF-BF.A.1a** — Write explicit function from context

👥 **WHO THIS IS FOR**

Algebra 1 teachers (Grades 9–10) introducing exponential functions Math teachers with multilingual learners / ELLs at WIDA levels 1–4 Teachers trying project-based learning Anyone who wants an immediately usable lesson

⬆️ **WANT THE FULL 5-DAY UNIT?**

This free lesson is **Day 1** of a complete PBL unit:

**Day 1:** Foundations — Chessboard hook **Day 2:** Compound Interest — Real Federal Reserve rates **Day 3:** U.S. Population — Census data 1790–2020 **Day 4:** Bacteria + Viral Spread — E. coli + SIR epidemic model **Day 5:** Student Choice Board — Culminating data-story project

The full unit also includes **50+ pages of instructional content, 8 labeled diagrams and visual concept anchors, detailed step-by-step solutions, two complete rubrics, a 30-term glossary with embedded formulas, extension activities, and differentiation strategies**.

→ [Get the full 5-day PBL unit here]

**Exponential Growth & Decay PBL | Real-World Algebra 1 Project | ELL Scaffolded**